SAP upgrade using SUM tool

Sure, let's break down SAP upgrades using the Software Update Manager (SUM) tool in detail, followed by 20 important one-liner interview questions.

SAP Upgrade using SUM Tool: A Detailed Overview

The SAP Software Update Manager (SUM) is a comprehensive, multi-purpose tool provided by SAP to perform various system maintenance activities, including:

SAP Releases Upgrades: Moving from an older SAP release to a newer one (e.g., ECC 6.0 to S/4HANA).
Enhancement Package (EHP) Installations: Applying EHPs to existing SAP systems.
Support Package Stack (SPS) Updates: Applying cumulative support packages.
Database Migrations: Changing the database platform (e.g., Oracle to HANA) – often combined with an upgrade.
Conversion to SAP S/4HANA: The primary tool for converting existing SAP ECC systems to S/4HANA.

SUM simplifies and automates many complex steps involved in these processes, reducing manual effort and potential errors. It operates in phases, guiding the user through the entire lifecycle.

Key Concepts & Advantages of SUM:

Minimizes Downtime: SUM employs a "near-zero downtime" (NZDT) or "downtime optimized" approach using parallel processing, shadow system technology, and in-place conversion techniques. It splits the upgrade into phases, allowing the productive system to run during much of the upgrade.
Shadow System: SUM creates a "shadow system" (a copy of the repository and database objects) in the background. Most of the technical upgrade activities (imports, conversions) are performed on this shadow system, leaving the productive system untouched until the final switchover.
Pre-checks and Validations: SUM performs extensive pre-checks to identify potential issues (e.g., missing prerequisites, inconsistent data) before and during the upgrade process.
Error Handling and Resume Capability: SUM is robust; if an error occurs, it provides detailed logs and allows you to resolve the issue and resume the process from where it stopped.
Guided Procedure: It's a wizard-driven tool with a user-friendly web interface, guiding the administrator step-by-step.
Reduced Manual Effort: Automates many tasks that would otherwise be manual and error-prone.
Logging and Monitoring: Provides detailed logs and monitoring capabilities throughout the upgrade process.

Phases of an SAP Upgrade using SUM:

SUM divides the upgrade into several logical phases, broadly categorized into roadmap steps. While the exact phase names might vary slightly between SUM versions and scenarios (e.g., standard upgrade vs. S/4HANA conversion), the core flow remains similar.

Here's a common breakdown of the major phases:

1. Preparation Phase (PREP_PHASE)

Initialization: SUM extracts itself and prepares the environment.
Configuration: You define system parameters, provide stack XML file, and specify upgrade options.
Source System Analysis: SUM collects information about the current system landscape, kernel, database, OS, and installed components.
Check Requirements: Verifies prerequisites like disk space, memory, OS patches, database parameters, and kernel versions.
Download & Extraction: Verifies the availability of required software components (downloaded via Maintenance Planner/MOPZ) and extracts them.
Tool-Specific Checks: Runs checks to ensure the environment is ready for the upgrade.
Lockdown: Prevents further changes to the system configuration (e.g., transports) during the upgrade.

2. System Analysis Phase (MAIN_PHASE/ACT_UPG_PHASE)

DDIC Activation and Downtime Minimization: SUM identifies dictionary objects that need activation and prepares for downtime minimization strategies (e.g., parallel processing, shadow system).
Shadow System Creation (SHDVIEWS): This is a critical step. SUM creates a shadow repository, which is a copy of your system's ABAP Dictionary objects (tables, indexes, views). The upgrade activities like import, modification adjustment, and activation will primarily happen on this shadow system.
Modification Adjustment (SPDD/SPAU): This is a crucial step for handling customer modifications.
- SPDD (Dictionary Object Adjustment): SUM identifies customer modifications to SAP standard dictionary objects. You perform these adjustments in the shadow system (usually through the SPRO transaction after SUM has prepared the phase). This phase occurs before the main import.
- SPAU (Program Object Adjustment): SUM identifies customer modifications to SAP standard program objects. This adjustment happens after the import phases, once the new SAP release objects are available.
Pre-processing (PREP_PHASE): This might involve initial import of support packages or small preparations before the main import.

3. Execution Phase (EXEC_PHASE)

Import of Components (DOWNTIME_PREP/UPG_PREP): SUM imports the new software components into the shadow system. This is where the bulk of the new software is introduced.
Conversion (if applicable, e.g., S/4HANA): For S/4HANA conversions, this phase includes major data model transformations and conversions.
Post-processing (POST_PHASE): This can involve activities like activation of new objects, regeneration of programs, and other post-import tasks.

4. Downtime Phase (DOWNTIME_PHASE)

This is the most critical phase as the production system is unavailable.

Locking the System: All users are logged off, and the system is shut down.
Database Updates: Critical database changes and schema adjustments take place.
Shadow System Takeover: The shadow system becomes the new productive system. This involves renaming/swapping database tables and indexes, making the new release code active.
Final Import and Activation: Remaining imports and activations that could not be done in the shadow system are completed.
SPAU Adjustment: If not done earlier, you perform SPAU (program object) adjustments.
Generation and Clean-up: Programs are regenerated, and temporary objects from the shadow system are cleaned up.

5. Post-Processing Phase (POST_PHASE)

Starting the System: The upgraded SAP system is brought online.
Post-Upgrade Activities:
- Kernel update and start services.
- Run transaction SICK (System Consistency Check).
- Run transaction SMIGR_UPG (for database-specific checks).
- Perform database statistics updates.
- Perform ABAP load generation (SGEN).
- Schedule standard jobs (e.g., background jobs for consistency checks, reorgs).
- Delete old transport requests.
- Update printer configurations.
- Post-upgrade health checks.
- Implement and adjust customer-specific configurations.
- Client copy (if required).
- Verify integration with other systems (interfaces).

High-Level Steps for an Upgrade with SUM:

Preparation & Planning:
- Define project scope, timeline, and resources.
- Prerequisites: Ensure OS, DB, hardware meet minimum requirements.
- Maintenance Planner: Use Maintenance Planner (on SAP Support Portal) to generate the stack.xml file. This file defines the target landscape and contains all required download information. It is crucial for ensuring consistency and compatibility of all components.
- Download all required software components (SAR/ZIP files) as specified by stack.xml.
- Update the SAPCAR utility to the latest version.
- Update Kernel: Update the current system's kernel to a SUM-compatible version (usually the latest available for the current release).
- Implement relevant SAP Notes for the specific upgrade.
- Backup: Perform a full and consistent database backup.
- Communicate downtime to business users.
SUM Tool Deployment:
- Download the SUM tool from SAP Support Portal.
- Extract the SUM archive (SAPCAR -xvf SUM*.SAR).
- Place it in a designated directory (e.g., /usr/sap/<SID>/SUM on Unix/Linux, C:\usr\sap\<SID>\SUM on Windows).
Start SUM:
- Execute the STARTUP script (e.g., STARTUP confighostagent on Linux) to configure the SAP Host Agent to run SUM.
- Access the SUM web UI through a browser (typically http://<hostname>:1128/lmsl/sumabap/<SID>/sluigui).
- Log in with sidadm user or an administrative user.
Execute Upgrade Phases:
- Follow the SUM wizard prompts.
- Provide the stack.xml file.
- Specify download directory for patches.
- Address any pre-checks or error messages.
- Execute SPDD/SPAU adjustments as prompted by SUM.
- Monitor the progress through the web UI and logs (SUM/abap/log).
Post-Upgrade Activities:
- Perform system consistency checks (SICK, SMIGR_UPG).
- Generate ABAP loads (SGEN).
- Update database statistics.
- Schedule standard background jobs.
- Perform thorough functional testing.
- Verify interfaces and integrations.
- Perform a new full backup of the upgraded system.

Best Practices:

Documentation: Maintain meticulous documentation of every step, decision, and issue encountered.
Run Book: Create a detailed run book for the upgrade, including all steps, commands, and expected outcomes.
Mock Upgrades: Perform several "mock" upgrade runs in a dedicated sandbox or development environment to identify and resolve issues before hitting production.
Sizing: Re-evaluate system sizing for the new release, especially for S/4HANA.
Knowledge Transfer: Ensure the Basis team is well-versed with the new release and its features.
SAP Notes: Pay close attention to all relevant SAP Notes, especially those for the specific SUM version and your target release.
Communication: Keep all stakeholders informed about the progress and any potential delays.

20 One-Liner Important Interview Questions on SAP Upgrade using SUM:

What is the primary purpose of the SAP Software Update Manager (SUM)?
- To perform system maintenance activities like upgrades, EHP installations, and support package updates.
Name two key advantages of using SUM for an SAP upgrade.
- Minimizes downtime using shadow system technology and automates complex steps.
What is a "shadow system" in the context of SUM, and why is it important?
- A temporary copy of the repository for performing upgrade activities while the productive system runs, minimizing downtime.
What is the significance of the stack.xml file in a SUM-based upgrade?
- It defines the target system landscape and lists all required software components for the upgrade, ensuring consistency.
Which SAP tool is used to generate the stack.xml file?
- SAP Maintenance Planner.
During which SUM phase do you typically adjust ABAP Dictionary objects (SPDD)?
- During the MAIN_PHASE or PREP_PHASE before the main import.
During which SUM phase do you typically adjust ABAP program objects (SPAU)?
- During the POST_PHASE after the main import and activation.
What is the "Downtime Phase" in a SUM upgrade?
- The critical phase where the production system is shut down for final cutover and database changes.
What utility is used to extract the SUM tool and other .SAR files?
- SAPCAR.
Before starting a SUM upgrade, what critical pre-activity involving a backup must be performed?
- A full and consistent database backup of the source system.
How do you access the SUM tool's graphical user interface?
- Through a web browser using a specific URL (e.g., http://<hostname>:1128/lmsl/sumabap/<SID>/sluigui).
What is SGEN used for in the post-upgrade phase?
- To generate ABAP loads for programs and screens, improving system performance.
Why is it important to update the kernel of the existing system before starting SUM?
- To ensure compatibility with the SUM tool and its functionalities.
What is the purpose of the saproot.sh script (on Unix/Linux) after a kernel update?
- To set correct ownership and permissions for critical kernel executables.
What does "NZDT" stand for in the context of SAP upgrades?
- Near-Zero Downtime.
Name one check you would perform immediately after the system comes up from an upgrade.
- Run transaction SICK (System Consistency Check) or check SM21 logs.
Can SUM be used for a database migration (e.g., Oracle to HANA) in conjunction with an upgrade?
- Yes, it is often used for combined upgrade and database migration scenarios (e.g., DMO of SUM).
Why are "mock upgrades" important before a production system upgrade?
- To identify and resolve potential issues in a non-production environment, reducing risks for the actual upgrade.
What is the significance of the LOCK_MODE parameter in SUM?
- It controls how the system is locked during upgrade phases, affecting user access.
Which OS-level user typically starts and controls the SUM process?
- The <sapsid>adm user (on Unix/Linux) or <SID>adm on Windows.

Rakshit Ranjan Singh

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